Regional cerebral blood flow characteristics of the Sturge-Weber syndrome

Cerebral Blood Flow, Brain Injury, and Aortic-Pulmonary Collateral Flow After the Fontan Operation

Patients with a single ventricle develop aortopulmonary collaterals (APCs) whose flow has been shown to be inversely proportional to cerebral blood flow (CBF) in a previous cross-sectional study. Longitudinal CBF and APC flow in patients with Fontan physiology adjusting for brain injury (BI) has never been reported. Decreased CBF and BI may adversely impact neurodevelopment. A prospective longitudinal cohort of 27 patients with Fontan physiology (aged 10 ± 1.9 years, 74% male) underwent cardiac and brain magnetic resonance imaging 3 to 9 months and 6.0 ± 1.86 years after Fontan operation to measure the CBF and APC flow and to reassess the BI (focal BI, generalized insult, and hemorrhage). CBF was measured using jugular venous flow and APC flow was measured by the difference between aortic flow and caval return. Multivariate modeling was used to assess the relation between the change in APC flow and BI. A strong inverse relation was found between CBF/aortic flow change and APC flow/aortic flow and APC flow/body surface area change (R2 = 0.70 and 0.72 respectively, p <0.02). Overall, the CBF decreased by 9 ± 11% and the APC flow decreased by 0.73 ± 0.67 l/min/m2. The evolution of CBF and APC flow were significantly and inversely related when adjusting for time since Fontan operation, gender, and BI on the multivariate modeling. Every unit increase in APC flow change was associated with an 8% decrease in CBF change. In conclusion, CBF and APC flow change are inversely related across serial imaging, adjusting for time from Fontan operation, gender, and BI. CBF and APC aortic flow decrease over a 6-year period. This may adversely impact neurodevelopment. Because APCs can be embolized, this may be a modifiable risk factor. Clinical trials numbers: NCT02135081 and NCT02919956.

Arterial Spin-Labeling Perfusion Imaging in the Early Stage of Sturge-Weber Syndrome

BACKGROUND AND PURPOSE

Sturge-Weber syndrome is a rare congenital neuro-oculo-cutaneous disorder. Although the principal mechanism of Sturge-Weber syndrome is characterized by a leptomeningeal vascular malformation, few data regarding perfusion abnormalities of the brain parenchyma are available. Therefore, the aim of this study was to assess the diagnostic performance of arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome before 1 year of age until 3.5 years of age. We hypothesized that a leptomeningeal vascular malformation has very early hypoperfusion compared with controls with healthy brains.

MATERIALS AND METHODS

We compared the CBF using arterial spin-labeling perfusion imaging performed at 3T MR imaging in the brain parenchymal regions juxtaposing the leptomeningeal vascular malformation in patients with Sturge-Weber syndrome (n = 16; 3.5 years of age or younger) with the corresponding areas in age-matched controls with healthy brains (n = 58). The analysis was performed following two complementary methods: a whole-brain voxel-based analysis and a visual ROI analysis focused on brain territory of the leptomeningeal vascular malformation.

RESULTS

Whole-brain voxel-based comparison revealed a significant unilateral decrease in CBF localized in the affected cortices of patients with Sturge-Weber syndrome (P < .001). CBF values within the ROIs in patients with Sturge-Weber syndrome were lower than those in controls (in the whole cohort: median, 25 mL/100g/min, versus 44 mL/100g/min; P < .001). This finding was also observed in the group younger than 1 year of age, emphasizing the high sensitivity of arterial spin-labeling in this age window in which the diagnosis is difficult.

CONCLUSIONS

Arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome can help to diagnose the disease by depicting a cortical hypoperfusion juxtaposing the leptomeningeal vascular malformation.

Reliability and Clinical Correlation of Transcranial Doppler Ultrasound in Sturge-Weber Syndrome

BACKGROUND

The reproducibility of transcranial Doppler (TCD) ultrasound measurements in Sturge-Weber syndrome (SWS) and TCD's ability to predict neurological progression is unknown.

METHODS

In 14 individuals with SWS, TCD measured mean flow velocity, pulsatility index, peak systolic velocity, and end-diastolic velocity in the middle, posterior, and anterior cerebral arteries of the affected and unaffected hemisphere. TCD was performed either once (n = 5) or twice in one day (n = 9). We assessed the reproducibility of the measurements performed twice on the same day on subjects and compared the TCD measurements to previously published age-matched controls. Clinically obtained neuroimaging was scored for extent and severity of SWS brain involvement. Patients were prospectively assigned SWS neuroscores.

RESULTS

Middle cerebral artery velocity (r = 0.79, P = 0.04, n = 7), posterior cerebral artery velocity (r = 0.90, P = 0.04, n = 5), and anterior cerebral artery pulsatility index (r = 0.82, P = 0.02, n = 7) were reproducible TCD measurements comparing same-day percent side-to-side differences. In subjects with SWS, affected and unaffected mean peak systolic velocity and end-diastolic velocity in the middle, posterior, and anterior cerebral arteries were globally lower compared with age-matched control subjects. Subjects with the lowest affected middle cerebral artery velocity had the greatest worsening in the total neurological score between time 1 and 2 (r = -0.73, P = 0.04, n = 8) and the most severe magnetic resonance imaging involvement of the affected frontal lobe (r = -0.82, P = 0.007, n = 9).

CONCLUSIONS

TCD may be a reliable measure with potential clinical value, indicating that blood flow may be globally decreased in SWS patients with unilateral brain involvement.

Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction

BACKGROUND

Patients with a single ventricle experience a high rate of brain injury and adverse neurodevelopmental outcome; however, the incidence of brain abnormalities throughout surgical reconstruction and their relationship with cerebral blood flow, oxygen delivery, and carbon dioxide reactivity remain unknown.

METHODS

Patients with a single ventricle were studied with magnetic resonance imaging scans immediately prior to bidirectional Glenn (pre-BDG), before Fontan (BDG), and then 3 to 9 months after Fontan reconstruction.

RESULTS

One hundred sixty-eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age, 4.8±1.7 months), 118 BDG (2.9±1.4 years), and 54 after Fontan (2.4±1.0 years). Nonacute ischemic white matter changes on T2-weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontan compared with pre-BDG patients (P<0.05). BDG patients had significantly higher cerebral blood flow than did Fontan patients. The odds of discovering brain injury with adjustment for surgical stage as well as ≥2 coexisting lesions within a patient decreased (63%-75% and 44%, respectively) with increasing amount of cerebral blood flow (P<0.05). In general, there was no association of oxygen delivery (except for ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury.

CONCLUSIONS

Significant brain abnormalities are commonly present in patients with a single ventricle, and detection of these lesions increases as children progress through staged surgical reconstruction, with multiple coexisting lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater cerebral blood flow than did Fontan patients and that an inverse association exists of various indexes of cerebral blood flow with these brain lesions. However, CO₂ reactivity and oxygen delivery (with 1 exception) were not associated with brain lesion development.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02135081.

A unique phenotype in a patient with a rare triplication of the 22q11.2 region and new clinical insights of the 22q11.2 microduplication syndrome: a report of two cases

Background

The rearrangements of the 22q11.2 chromosomal region, most frequently deletions and duplications, have been known to be responsible for multiple congenital anomaly disorders. These rearrangements are implicated in syndromes that have some phenotypic resemblances. While the 22q11.2 deletion, also known as DiGeorge/Velocardiofacial syndrome, has common features that include cardiac abnormalities, thymic hypoplasia, characteristic face, hypocalcemia, cognitive delay, palatal defects, velopharyngeal insufficiency, and other malformations, the microduplication syndrome is largely undetected. This is mainly because phenotypic appearance is variable, milder, less characteristic and unpredictable. In this paper, we report the clinical evaluation and follow-up of two patients affected by 22q11.2 rearrangements, emphasizing new phenotypic features associated with duplication and triplication of this genomic region.

Case Presentation

Patient 1 is a 24 year-old female with 22q11.2 duplication who has a heart defect (ostium secundum atrial septal defect) and supernumerary teeth (hyperdontia), a feature previously not reported in patients with 22q11.2 microduplication syndrome. Her monozygotic twin sister, who died at the age of one month, had a different heart defect (truncus arteriousus). Patient 2 is a 20 year-old female with a 22q11.2 triplication who had a father with 22q11.2 duplication. In comparison to the first case reported in the literature, she has an aggravated phenotype characterized by heart defects (restrictive VSD and membranous subaortic stenosis), and presented other facial dysmorphisms and urogenital malformations (ovarian cyst). Additionally, she has a hemangioma planum on the right side of her face, a feature of Sturge-Weber syndrome.

Conclusions

In this report, we described hyperdontia as a new feature of 22q11.2 microdeletion syndrome. Moreover, this syndrome was diagnosed in a patient who had a deceased monozygotic twin affected with a different heart defect, which corresponds to a phenotypic discordance never reported in the literature. Case 2 is the second clinical report of 22q11.2 triplication and presents an aggravated phenotype in contrast to the patient previously reported.

Sturge–Weber syndrome and epilepsy: an argument for aggressive seizure management in these patients

Sturge-Weber syndrome (SWS) involves vascular malformations of the skin (facial port-wine stain), eye (glaucoma) and the brain (leptomeningeal angioma). Children born with a port-wine stain on the upper part of the face are also at risk for brain involvement. These infants and young children often develop seizures and other neurologic impairments. Progression in neurologic deficits does occur in some patients, but this is quite variable. A diagnosis of brain involvement is made with head computed tomography and contrast-enhanced MRI, but the sensitivity of standard imaging in young asymptomatic infants is low. Seizures occur in more than 75% of affected individuals. Clinical course and functional imaging suggest a role for both cerebral perfusion impairments and seizures in the development of neurologic deficits. Several controversies exist in the management of seizures and other neurologic impairments in SWS. Continued efforts are needed to develop a multicentered network for SWS clinical trials. Future research should be focused on this goal and on studies to improve our understanding of the cause(s) and molecular neuropathology of SWS.

Updates and future horizons on the understanding, diagnosis, and treatment of Sturge-Weber syndrome brain involvement

AIM

To review recent developments in the understanding, diagnosis, and treatment of Sturge-Weber syndrome (SWS).

METHOD

Members of the Brain Vascular Malformation Consortium Sturge-Weber Syndrome National Workgroup contributed their expertise to review the literature and present promising directions for research.

RESULTS

The increasing number of reports dealing with SWS over the last decade reflects progress in the diagnosis and understanding of the neurological involvement. The proliferation of centers and advocacy groups to care for patients with SWS and to stimulate research has aided the development of new insights into the clinical manifestations and the pathophysiology of neurological progression, and the development of novel hypotheses to direct future research. Many key questions remain, but the tools and networks to answer them are being developed.

INTERPRETATION

This review summarizes important new knowledge and presents new research directions that are likely to provide further insights, earlier diagnosis, improved treatments, and possibly, prevention of this syndrome.

Epilepsy in the setting of neurocutaneous syndromes

The neurocutaneous syndromes are characterized by congenital dysplastic abnormalities involving the skin and nervous system. The commonest neurocutaneous syndromes manifesting epilepsy are tuberous sclerosis and the Sturge-Weber syndrome. Neurofibromatosis and other lesser-known entities, such as epidermal nevus syndrome, are also known to be accompanied by epilepsy. These syndromes are not related to one another. This article reviews what has been learned about the epileptic syndromes in these disorders.

Neuropsychological features and risk factors in children with Sturge-Weber syndrome: four case reports

Sturge-Weber Syndrome (SWS) is a rare neurocutaneous disorder involving facial capillary malformation (port-wine birthmark) and vascular malformation of the brain that is frequently associated with epilepsy, stroke-like episodes, cognitive deficits, motor impairment, and/or visual field cut. The four cases presented here (ages 8-9, two females) illustrate the broad range of physiologic involvement and associated neuropsychological functioning in SWS, and argue against the idea of a "typical" SWS neuropsychological presentation. Rather, we highlight a preliminary collection of disease status/severity factors thought to impact neuropsychological presentation in SWS, including degree of cortical involvement (unilateral versus bilateral; posterior only versus posterior/anterior), age at time of seizure onset, extent of seizure control, history of stroke-like episodes, and magnitude of neurologic decline/deficit. We discuss the need for broad-based assessment in this medical population, as various impairment combinations (e.g., perceptual, language, executive) create unique presentations as well as the need for individualized intervention.

Sturge-Weber syndrome associated with arteriovenous malformation in a patient presenting with progressive brain edema and cyst formation

Sturge-Weber syndrome (SWS) is a neurocutaneous disorder presenting with a facial port-wine stain, along with an occipital leptomeningeal angiomatosis that is typically located ipsilateral to the stain. In this paper, the authors present a rare case of SWS associated with an arteriovenous malformation (AVM) instead of an angiomatosis in the ipsilateral occipital lobe. While the patient was in the care of the authors, the AVM progressively enlarged, and was accompanied by progressive stenoocclusive changes of the venous system. The resulting brain edema finally brought about a serious neurological condition 13 years after the initial diagnosis. Transarterial embolization and medical treatments decreased the edema. Subsequently, however, a large intraparenchymal cyst appeared, aggravating the patient's motor weakness. Aspiration of the cyst ameliorated these symptoms. The analysis of the fluid from the cyst revealed that it contained a very high concentration of protein. Although there is no proven pathogenic mechanism to explain these protein concentrations and the enlargement of the AVM, the authors hypothesize that the progressive edema resulted from a synergic augmentation of the inflow from the AVM and the progressive obstruction of venous drainage that is a hallmark of SWS. The formation of the cyst probably resulted from the blood vessel hyperpermeability that is inherent to SWS.

Transcranial Doppler ultrasound in children with Sturge-Weber syndrome

Transcranial Doppler ultrasound is a noninvasive vascular assessment technique proved useful in the management of pediatric disorders predisposed to stroke and may have similar utility for Sturge-Weber syndrome. Eight children with Sturge-Weber syndrome had velocities measured in the major cerebral arteries via the Stroke Prevention Trial in Sickle Cell Anemia methodology. Velocities and pulsatility indexes were compared between the unaffected and affected sides. All subjects had reduced velocity on the affected side; the mean middle cerebral artery percentage difference was 20% (95% CI, 15%-25%). Pulsatility index was increased on the affected side; mean middle cerebral artery pulsatility index percentage difference, 34% (95% CI, 15%-53%). Six subjects also had reduced posterior cerebral artery velocity on the affected side. Side-to-side differences in middle cerebral artery and posterior cerebral artery velocities correlated with severity of MRI asymmetry (Spearman rho = 0.88, P = .02). Decreased arterial flow velocity and increased pulsatility index in the middle cerebral artery and posterior cerebral artery suggests a high resistance pattern that may reflect venous stasis and may contribute to chronic hypoperfusion of brain tissue. Further study of Transcranial Doppler in children with Sturge-Weber syndrome is indicated.

The correlation between motor impairment and cerebral blood flow in Sturge-Weber syndrome

Recent studies of regional cerebral blood flow (rCBF) and cerebral metabolism in patients with Sturge-Weber syndrome (SWS) have demonstrated a regional decrease of CBF and metabolism in the affected hemisphere, which may reflect the neurological status of the patients. Therefore, in the present study, we use stable xenon computed tomography (xenon-CT) and/or (99m)technetium hexamethylprophylene amine oxime ((99mTc)HMPAO) single photon emission computed tomography (SPECT) to determine whether the degree of cerebral hemodynamic disturbance correlates with the severity of motor impairment in 5 children with Sturge-Weber syndrome. We found that 5 patients had great variation in clinical progression and outcome, but MR imaging investigations all revealed extensive but stable abnormalities. rCBF, assessed by stable xenon-CT and/or (99mTc)HMPAO-SPECT, showed perfusion defect in all subjects. However, the xenon-CT disclosed reduction of rCBF and cerebrovascular reactivity in patients with severe motor paralysis. The total CBF and rCBF detected by xenon-CT were improved after clinical status was stabilized. We conclude that the motor function impairment in patients with SWS appeared to better correlate with the degree of rCBF impairment than with the abnormalities in conventional neuroimaging. Therefore, the quantitative CBF study is one of the diagnostic modality of choice in evaluating the neurological status in patients with SWS.

Advances in Sturge-Weber syndrome

PURPOSE OF REVIEW

Recent neuroimaging, clinical and molecular neuropathologic studies have provided new insights into the neurologic aspects of Sturge-Weber syndrome and are summarized here.

RECENT FINDINGS

Molecular studies suggest that abnormal brain blood vessel vasoactive and extracellular matrix molecule expression, as well as aberrant brain vascular innervation, contribute to the vascular malformation and its consequences. New magnetic resonance sequences may be useful for the early diagnosis of Sturge-Weber syndrome and perfusion magnetic resonance imaging, single photon emission computed tomography imaging, and positron emission tomography imaging studies are suggesting that decreased brain blood flow combined with altered hemodynamics during prolonged seizures may contribute to the neurologic declines in Sturge-Weber syndrome.

SUMMARY

Recent advances in our understanding of the neurologic issues offer promise for preventing brain injury in Sturge-Weber syndrome. More research is needed to translate advances in molecular research and neuroimaging advances into new treatment strategies for the disease.

Neurocutaneous syndromes: behavioral features

Neurocutaneous syndromes are disorders characterized by a neurological abnormality and cutaneous manifestations. Three of the more common neurocutaneous syndromes are Sturge-Weber syndrome, tuberous sclerosis, and neurofibromatosis. This review focuses on the cognitive and behavioral features of these syndromes.

Pathophysiology of Sturge-Weber syndrome

Sturge-Weber syndrome is a neurocutaneous disorder classically presenting with a facial port-wine stain, vascular eye abnormalities, and an ipsilateral occipital leptomeningeal angioma. Children with Sturge-Weber syndrome often develop progressive neurologic problems. Data on the pathophysiology of Sturge-Weber syndrome are briefly reviewed. The embryologic, genetic, and pathologic considerations are discussed, as are theories regarding the mechanisms of the degenerative brain changes. Sturge-Weber syndrome likely results from an early embryologic malformation of vascular development affecting the development of the nearby skin, eye, and brain structures. Studies suggest that complex molecular interactions contribute to the abnormal development and function of blood vessels in Sturge-Weber syndrome. Neurologic deterioration in Sturge-Weber syndrome is likely secondary to impaired blood flow to the brain and is worsened by the presence of seizures. Insights from related areas are discussed, and future research studies are suggested.

Quantitative analysis of gray- and white-matter volumes and glucose metabolism in Sturge-Weber syndrome

The progressive nature of Sturge-Weber syndrome is well known, but the mechanisms of focal cortical and subcortical degeneration in this disorder are poorly understood. In the present study, we assessed the structural and functional integrity of gray and white matter in unihemispheric Sturge-Weber syndrome using quantitative magnetic resonance imaging (MRI) volumetry and MRI-based partial volume correction of [18F]fluorodeoxyglucose positron emission tomographic (PET) images. Gray- and white-matter volumes and glucose metabolism were measured in three brain regions (parieto-occipital underneath the angioma, temporal, and frontal) in six children with Sturge-Weber syndrome (two infants, ages 6 and 9 months; four older children, ages 4 to 14 years), all with unilateral parieto-occipital leptomeningeal angiomatosis. The gray-matter volumes ipsilateral to the angioma were smaller in all children, with the posterior regions underneath the angioma the most affected. In the infants, the white-matter volumes were increased in the region of the angioma, whereas in the regions remote from the angioma in the infants and in all regions of the older children, there were large decreases in white-matter volume. The decreases of frontal and temporal white-matter volume were more pronounced than the corresponding gray-matter volume decreases. The PET studies showed severe hypometabolism in the parieto-occipitalregion underneath the angioma in all of the children. However, the two infants showed glucose hypermetabolism in the frontal and temporal cortical gray matter, whereas these regions had relatively preserved metabolism in the older patients. These results demonstrate differential involvement of gray and white matter in Sturge-Weber syndrome. Both structural and functional abnormalities extend well beyond the angioma, indicating widespread abnormalities of growth and development of the affected hemisphere. Furthermore, whereas increased white-matter volume underlying the angioma may be seen in infants, ipsilateral white-matter regions outside the angioma show volume loss both in infants and in older patients. Extensive gray- and white-matter volume loss and hypometabolism ipsilateral to the angioma likely contribute to the frequently observed progressive cognitive dysfunction in these patients, regardless of the extent of the angioma.

Central nervous system structure and function in Sturge-Weber syndrome: evidence of neurologic and radiologic progression

Sturge-Weber syndrome is characterized by the presence of a port-wine nevus, epilepsy, stroke-like episodes, headache, and developmental delay. We studied 20 cases to test the hypothesis that decreased cerebral blood flow alters neurologic function by affecting cellular glucose metabolism. Group A consisted of 10 patients with a mean age of 1.75 years and early seizure onset (6.8 months), whereas group B was composed of older patients (mean age, 15.3 years) with later onset of seizures (3.7 years). Neurologic disease was more severe in group A, but group B had more widespread structural brain defects - shown on computed tomographic scans and magnetic resonance imaging - and metabolic brain defects shown on hexamethylpropyleneamine oxime and [18F] fluorodeoxyglucose single photon emission computed tomographic scans. Six group A cases had hypoperfusion at baseline and five of nine had worsening of perfusion and glucose metabolism 1 year later. A total of 119 stroke-like episodes occurred in six group A cases and eight group B cases; there were 65% fewer strokes in children treated with aspirin. The data suggest that progressive hypoperfusion and glucose hypometabolism are associated with neurologic deterioration in Sturge-Weber syndrome. Longitudinal studies are needed to better define the natural history of disease and to evaluate the safety and efficacy of aspirin therapy.

High prevalence of bihemispheric structural and functional defects in Sturge-Weber syndrome

Abnormal cerebral venous drainage is associated with hypoxia and glucose deprivation, which can account for progressive neurologic deterioration in Sturge-Weber syndrome. Although developmental delay is common in Sturge-Weber syndrome, bihemispheric calcification is uncommon. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to study the neuroanatomy, while single photon emission computed tomography (SPECT) was used concurrently to evaluate perfusion and glucose metabolism using 99mTc hexamethylpropyleneamine oxime (HMPAO) and [18F] fluorodeoxyglucose (FDG), respectively. Ten patients (10 to 22 years of age) with previously diagnosed Sturge-Weber syndrome, port-wine nevi, and clinical evidence of seizures or stroke-like episodes were studied. Five children with onset of seizures in the first year of life had overall clinical severity comparable to that of children with later-onset seizures. Calcification was present in both hemispheres in one patient; six additional patients had other radiologic evidence of bihemispheric disease; SPECT studies detected bihemispheric disease in four cases. Our study is the first to concurrently evaluate structure, perfusion, and glucose metabolism in Sturge-Weber syndrome and to show a mismatch between functional and structural brain imaging in both cerebral hemispheres. Widespread abnormalities of cerebral perfusion and glucose metabolism might explain the high prevalence of developmental delay associated with Sturge-Weber syndrome. Longitudinal studies are needed to define better the natural history of neurologic deterioration and radiologic progression that relates to central nervous system circulatory dysfunction in Sturge-Weber syndrome.

Neurocutaneous syndromes

Many of the neurocutaneous disorders are more common than once suspected, in part because patients with milder forms of the disorders are now more likely to be recognized. Improved diagnostic studies and increasingly specific medical and surgical therapy allow some previously untreatable complications to be successfully managed. Genetic linkage analysis has localized the abnormal gene for some of the hereditary neurocutaneous disorders onto specific chromosomes, and newly developed clinical diagnostic criteria have improved our ability to establish a definite diagnosis in less obvious patients. Thus, the outlook for these patients is no longer uniformly pessimistic.